Upper Primary Science ( Plant Transport System) - Free Printable

Problem Analysis:

The image provided is a scanning electron microscope (SEM) image of a leaf surface. The question revolves around understanding the structure and function of stomata, which are the tiny openings visible in the image.

#### Key Concepts:
1. Stomata: These are small pores found on the epidermis of leaves, stems, and other plant organs. They allow for gas exchange (e.g., intake of CO₂ and release of O₂ during photosynthesis) and regulate water loss through transpiration.
2. Transpiration: The process by which water vapor is released from plants, primarily through stomata.
3. Surface Area and Transpiration: A larger surface area of leaves generally leads to higher rates of transpiration because there are more stomata available for water vapor to escape.

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Solution to Each Part:

#### Question 2:
##### a) State the name of the tiny opening in the picture.
- The tiny openings visible in the image are called stomata.

##### b) State two ways in which these tiny openings are useful to the plant.
1. Gas Exchange: Stomata allow for the exchange of gases essential for photosynthesis. Specifically, they facilitate the intake of carbon dioxide (CO₂) and the release of oxygen (O₂).
2. Transpiration: Stomata regulate the loss of water vapor from the plant, which helps in cooling the plant and in the transport of water and nutrients from the roots to the leaves.

##### c) State if there are more of these tiny openings on the top or underside of the leaf.
- Generally, most plants have more stomata on the underside of the leaf. This arrangement helps minimize water loss because the underside of the leaf is typically exposed to less direct sunlight and lower wind speeds, reducing evaporation.

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#### Question 3:
##### a) State the relationship between the surface area of the leaf and the rate of transpiration of the plant.
- The surface area of the leaf is directly proportional to the rate of transpiration. A larger surface area means more stomata are present, allowing more water vapor to escape from the plant.

##### b) Explain your answer in (a).
- Transpiration occurs primarily through stomata. If the surface area of the leaf is larger, there will be more stomata available for water vapor to escape. Consequently, a larger surface area leads to a higher rate of transpiration. This relationship is crucial for plants, as it affects their ability to balance water uptake and loss, especially in environments with varying humidity and temperature conditions.

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Final Answers:

#### Question 2:
- a) Stomata
- b)
1. Gas exchange (intake of CO₂ and release of O₂)
2. Regulation of transpiration (water loss)
- c) More stomata are typically found on the underside of the leaf.

#### Question 3:
- a) The surface area of the leaf is directly proportional to the rate of transpiration.
- b) A larger surface area means more stomata are present, allowing more water vapor to escape, thus increasing the rate of transpiration.

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Boxed Final Answer:

\[
\boxed{
\text{2. a) Stomata} \\
\text{ b) Gas exchange, regulation of transpiration} \\
\text{ c) Underside of the leaf} \\
\text{3. a) Directly proportional} \\
\text{ b) Larger surface area means more stomata, leading to higher transpiration.}
}
\]